The subject of this study is the politics of ethnic and racial relations in developing countries. It deals with a key aspect of population composition: the relation of ethnic composition to patterns of political participation and stability. The objective of this study, is to derive general propositions about the politics of ethnic relations from the concrete experience of ethnically-divided societies. The study centers on four major subject-areas: (1) the factors influencing the definition of ethnic group identity; (2) the sources of ethnic conflict; (3) the forms and patterns of ethnic politics; and (4) strategies of ethnic accommodation, focusing on the costs and benefits of alternative policies and techniques designed to reduce the level of ethnic conflict in divided societies. This last subdivision has rather clear relevance for policy, but the major thrust of the research is simply to identify and elaborate recurrent patterns of ethnic politics on a cross-cultural basis, building on untapped material already available in studies dealing with single countries or particular ethnic groups or movements.